Townsonia viridis, commonly known as the beech orchid, is a species of orchid endemic to Tasmania. It forms diffuse colonies with tiny, inconspicuous flowers and small, more or less round leaves and grows mainly in mossy places in myrtle beech forest.
Townsonia viridis is a terrestrial, perennial, deciduous, sympodial herbs which grows in small groups with the tubers connected by a fleshy root. It spreads through mossy patches and leaf litter. Each tuber produces one or two leaves. Both flowering and non-flowering plants have an erect, very thin leaf emerging at ground level. These leaves are pale green to yellowish and have wavy margins. They are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide with a petiole NaNsigfig=1NaNsigfig=1 long. Flowering plants also have a similar leaf on the flowering stem except that it lacks a petiole and is well above ground level. Up to four flowers NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide are borne on a brittle, fleshy flowering stem NaNsigfig=1NaNsigfig=1 high. The flowers are green with red blotches. The dorsal sepal is NaNsigfig=2NaNsigfig=2 long, about 4sigfig=1NaNsigfig=1 wide and forms a hood over the column. The lateral sepals are a similar length to the dorsal sepal but only half as wide. The petals are about 2.5sigfig=1NaNsigfig=1 long, 1sigfig=1NaNsigfig=1 wide and spread apart from each other. The labellum is a broad egg shape, NaNsigfig=2NaNsigfig=2 long and wide, folded lengthwise with the tip turned downwards. Flowering occurs from November to January.[1]
The beech orchid was first formally described in 1906 by Joseph Dalton Hooker who gave it the name Acianthus viridis and published the description in Flora Antarctica.[2] [3] In 1911 Rudolf Schlechter changed the name to Townsonia viridis.[4] The specific epithet (viridis) is a Latin word meaning "green".[5]
The beech orchid grows in permanently wet forests, especially those of myrtle beech. It is found mainly on the west coast of Tasmania.